FR2864204A1 - Signaling or lighting device for motor vehicle, has optical waveguides presenting longitudinal axis arranged such that part of emitted light assures signaling or lighting functions with increased and reduced light intensities - Google Patents

Abstract

The device has optical waveguides (G1, G2) arranged near a light source (L) and presenting a longitudinal axis. The axis is disposed transversal to main emission direction so that part of light from the source assures a signaling or lighting function with increased light intensity independent of the waveguides and a linear lighting or signaling function with reduced light intensity along the length of the waveguides.

Description

SIGNALING OR LIGHTING DEVICE, IN PARTICULAR FOR A VEHICLE

AUTOMOBILE.

  The invention relates to a signaling or lighting device, in particular for a motor vehicle, of the kind comprising at least one light source admitting a main direction of emission, and at least one elongate light guide of which one end is illuminated by the source, this guide being adapted to diffuse the light transversely to its length.

  EP-A-0 515 921 shows a device of this type intended to provide illumination inside the vehicle by being incorporated in a door handle. The light intensity in a direction orthogonal to the length of the light guide does not have a preferred area and remains relatively low.

  Or it is desirable that a signaling device or lighting, generally oriented towards the outside of a vehicle, to attract the attention of other motorists or pedestrians.

  The object of the invention is therefore, above all, to provide a signaling or lighting device of the kind defined above which makes it possible to better exploit the light emitted by the source and to provide at least one area of high luminous intensity combined with at least one an area of the light guide illuminating with less intensity.

  The invention also aims to provide a signaling device or lighting which, while being simple and robust, allows to mark well zones of a vehicle.

  According to the invention, a signaling or lighting device of the kind defined above is characterized in that the light guide, at least in the vicinity of the source, has a longitudinal axis arranged transversely to the main direction of emission so a part of the luminous flux of the source ensures, independently of the guide, a first function of signaling or lighting with a relatively high luminous intensity, and a second function of signaling or of linear illumination, of less luminous intensity , is ensured along the length of the light guide.

  In general, the light source can also emit in oblique directions, and the source provides the first signaling or lighting function in the main direction of emission, while the second signaling or linear lighting function is ensured according to the length of the light guide by emission in oblique directions.

  Advantageously, the device comprises an optical system associated with the light source to concentrate the emission along the main direction. The first signaling or lighting function, provided directly by the source, is thus reinforced.

  Preferably, the light source comprises at least one light-emitting diode which illuminates substantially on a half-sphere, and the light guide, at least in the vicinity of the source, has its longitudinal axis orthogonal to the main direction of emission.

  Several light guides can be associated with the same source by being angularly distributed around the main direction of transmission.

  The light guides may be rectilinear or curvilinear.

  The light source can be placed in a central position between at least two light guides, especially symmetrical with respect to the source, in particular aligned.

  The optical system associated with the light source for concentrating the emission may comprise a lens made of transparent material and having facets oriented at appropriate angles to ensure internal reflections of the light before its exit and to fulfill a target function. Such an optical system is also called a light engine.

  The device may include a plurality of light sources connected by transverse light guides.

  A light guide may include at least one neutral zone that does not provide cross-scattering of the light.

  The device may include a converging lens having a convex face applied against the source and oriented to create the main beam.

  A converging lens may be provided at the end of each adjacent guide of the source to collimate the light rays in the guide.

  The waveguides located on either side of the source may form a single piece having a housing for the light source, the faces of the housing corresponding to the end of the waveguides being convex to focus the light rays in the guides.

  The diffusion of light through the guide is provided by a face located at the rear relative to the emission. This face has streaks, or optical micro-patterns, and is preferably metallized to better reflect the light.

  The width of the scattering band can be determined to broaden the apparent luminance field at an angle of, for example, 10.

  As a variant, the source comprises a plurality of elementary sources distributed in at least two subsets, one of these subsets being associated with an optical system for providing a main signaling or lighting function, another subset cooperating with at least one light guide to provide a secondary function of great length.

  The invention consists, apart from the arrangements described above, in a certain number of other arrangements which will be more explicitly discussed below with regard to embodiments described with reference to the accompanying drawings, but which are not in no way limiting.

  In these drawings: 1 partially shows a device according to the invention in section along a plane passing through the longitudinal axis of the light guides located on either side of the light source; Fig. 2 is a section along line II-II of FIG. 1; Fig. 3 shows partially in perspective on a larger scale, seen from the rear, one end of the light guide; Fig. 4 is a perspective view taken away from the front of the light source with an optical lens for focusing the light, and the beginning of a light guide; Fig. 5 is a perspective view of the rear with respect to FIG. 4; Fig. Fig. 6 is a flood of light guide assemblies and a central optical system as previously described, on a smaller scale; Fig. 7 is a cross section of the light guide with illustration of the light path; Fig. 8 to FIG. 11 show possible alternative embodiments with rectilinear or curvilinear light guides; Fig. 12 illustrates a device with three aligned light guides, two light sources between two guides, and two extreme sources; Fig. 13 shows a light guide device 30 provided at each end with a light source and having unlighted neutral areas; Fig. 14 is a partial longitudinal section of a piece forming two light guides on either side of a housing for receiving the source; Fig. 15 is a section along the line XV-XV of FIG. 14, on a smaller scale and with the light source; Fig. 16 is a section along line XVI-XVI of FIG. 15; Fig. 17 is a perspective view, from the rear, of a variant of Fig.14 with a light source introduced into the housing; Fig. 18 is a perspective view from the front with respect to FIG. 17, and FIG. 19 is a diagram of an alternative embodiment with a source having multiple leds.

  Referring to Figs. 1 to 6 of the drawings, there can be seen a signaling device S for a motor vehicle intended to provide a "raised stop" function also designated by function CHMLS (Central High Mounted Lamp Stop). Of course, the signaling or lighting device according to the invention is not limited to this type of function.

  The device comprises a light source L constituted by a light emitting diode 1 adapted to emit, upwards according to Fig.l, along a main direction X-X and following directions B oblique with respect to the main direction X-X.

  An elongate light guide G1 is disposed with its longitudinal axis Y1 oriented transversely, at least in the vicinity of the diode 1. Preferably the axis Y1 is orthogonal to the main direction of emission XX. The light guide Gi may consist of an optical fiber, for example cylindrical with a circular cross section as illustrated in FIG. 3. The cross-section might be different from a circle. The end face E1 of the guide G1 adjacent to the source L is orthogonal to the axis Y1.

  A direction B is considered oblique when it is inclined with respect to the X-X direction by an angle sufficient to enter the guide Gi by the face El. This angle can be of the order of 30.

  The outer surface 1a of the emitting zone of diode 1 is substantially hemispherical. The face E1 is tangent to the surface 1a, parallel to the direction X-X.

  The guide G1 extends on the opposite side to the diode 1 over a relatively large length, especially greater than 500 mm, the diameter of the guide G1 being of the order of 8 mm.

  A second light guide G2 is advantageously provided in the alignment of G1, symmetrically with respect to X-X. The longitudinal axis Y2 of the guide G2 is in alignment with Y1.

  An optical system 2 is associated with the light source L to focus the emission in the X-X direction. The optical system 2 comprises a windshell 3 made of transparent material, for example plastic material.

  This windshield 3 forms a cup whose concavity is turned on the side opposite to the diode 1. The cross section of the concave surface of the windshield is formed by steps 3a at right angles provided to ensure a concentration of the light rays as illustrated in FIG. . 2 to the X-X axis. The rear surface 3b of the windscreen is substantially frustoconical and inclined at an angle favoring internal reflections. Lenses 3c forming a lens (see FIG 4) may be provided on the annular zones of the steps 3a located in planes orthogonal to the X-X direction. Pavers 3c convex surface forward are provided to accentuate the phenomenon of concentration of light rays. The central part of the concave zone of the windshield forms a semiconvex lens 4 whose convex face is turned towards the led 1.

  The windshell 3 comprises two diametrically opposed cylindrical housings 5a, 5b of axis orthogonal to the X-X direction and adapted to receive, in a controlled manner, the end of the guides G1, G2.

  The surface F of the guides G1, G2 located opposite the light output in the X-X direction is processed to reflect the light transversely to the axes Y1, Y2 of the guides, on the same side as the main transmission in the X-X direction.

  The treated surface F may comprise ridges or saw teeth 6 forming Fresnel prisms with a triangular section of edge orthogonal to the axes Y1, Y2 and to the direction X-X. The prisms thus formed may constitute the rear face of a blade 7 (FIG. 3) integrated with the tubular guides G1, G2 during the manufacturing process carried out by injection of transparent plastic material into a mold.

  The face 8 is set in a direction parallel to the axis Y1, Y2 while remaining orthogonal to the direction X-X.

  The surface F, in particular the oblique faces of the saw teeth 6, may be metallized.

  The saw teeth 6 could be replaced by optical micro-patterns (shaped holes adapted in the material) to improve the homogeneous appearance of the light guide. These optical micro-patterns are in particular obtained either directly by laser etching of the set rear face 8 of the guide G1, G2, or via patterns made in the mold during the injection. In this case the saw teeth 6 and / or the blade 7 would not be used.

  The width h (FIG. 3) of the diffusing band, that is to say the dimension of the surface F in a direction orthogonal to the plane passing through the axis of the guide and the direction XX, is calculated so as to widen the apparent luminance field for an observer. Advantageously, for a horizontal light guide G1, G2, the angle of the luminance field is +/- 10 with respect to the horizontal plane.

  In the case where the system is used in a substantially vertical direction, this angle of the luminance field is chosen more important in order to increase the visibility zone in a horizontal plane.

  As illustrated in FIG. 7, the cylindrical shape of the guide G1, with a circular cross section, makes it possible to obtain an enlargement of the diffusing zone by a classic magnifying glass effect.

  The operation of the signaling device 35 is as follows.

  When led 1 is on, a main transmission takes place in the X-X direction. The light intensity is concentrated by the lens 4 and by the optical device constituted by the windshield 3.

  This signaling function is concentrated with a relatively high light intensity.

  A second signaling function of great length, homogeneous, is obtained on both sides of the windshell 3 along the length of the guides G1, G2 from oblique rays such as B which undergo internal reflections in the guides to be returned by the surface F towards the front, that is to say on the same side as the main emission.

  The signaling device of the invention can thus be broken down into two complementary subassemblies: a central part corresponding to the diode 1 and to the windshield 3; this part is intended to perform the main function, function "stop raised" in the example considered; the function uses the internal reflection properties of the material of the windshield 3. The form presented is adaptable according to criteria of style and relative performance to satisfy the function; two appendices constituted by the light guides G1, G2 which make it possible to perform a function of very great homogeneous length, generating a fluid style to emphasize the shapes of a vehicle.

  Of course it is possible to achieve an asymmetrical linear function with respect to the windshield 3, to adapt to conventional signaling functions of great length to emphasize a vehicle outline, including the break type. It is indeed difficult, with conventional optical means, to install a light signal in almost inaccessible areas.

  Fig.6 shows the optical system with the two long guides G1, G2 extending on both sides of the windshield 3.

  The light guides allow, for example, to follow the turn of the rear window, or to follow a part of the body or the vehicle template.

  In the example considered, two diametrically opposite guides are provided on either side of the led 1. More than two guides could be provided, for example four outputs in the same plane, the outputs being offset by 90 angularly.

  The total length of the light guides may exceed 1300 mm. The shape of the guide is adaptable according to the style of the vehicle support. The central part formed by the windshield 3 can be round or rectangular with a large dimension of the order of 20 to 30mm as required.

  As illustrated in FIG. 14, it is advantageous to provide a convergent lens M on the input face of the light guide so as to collimate, that is to say make the light beam substantially parallel to the interior of the light guide. guide and thus increase the luminance towards the end Ni (Figs.3 and 6) of the guide remote from the led 1.

  This end N1 (Fig.3) is advantageously constituted by a flat face, orthogonal to the longitudinal axis of the guide and metallized to return the light inside the guide Gi or G2. The luminous efficiency of the system is thus improved.

  Many provisions can be adopted to carry out the signaling function.

  Fig.8 shows an asymmetric arrangement with two windscreens 3 and two corresponding juxtaposed sources, a single light guide G1 being associated with each windshield. The two light guides G1 are parallel, substantially vertical and rectilinear, and arranged on the same side of the windscreens 3.

  Fig.9 shows a provision with windshield 3 and source of light in the center and a light guide Gia starting from this windshield and winding substantially in a circular spiral with two towers located in a plane.

  Fig.10 shows a signaling device in the center with the windshield 3 with the light source. Two diametrically opposed light guides Glb, G2b start from this windshield and turn substantially on a half-turn in the opposite direction, in the same plane, so that the whole of the pattern has the shape of an S. In a variant the curves formed by the light guides may be left curves, not located in a plane.

  Fig.11 shows an alternative embodiment of Fig.8, with the two horizontal parallel guides G1, and located on the same side.

  Many functions can be realized, in particular: stop; lantern; direction indicator; recoil or other. The color of led 1 will be chosen accordingly.

  It is also possible to create different concepts always composed of a central optical system with light source, including led 1, and at least one complementary light guide to significantly increase the possibilities of style.

  It is possible to combine these components to achieve adaptable styles. Symmetrical versions are obtained by placing a main source of light in the center of the system, or at each end. Asymmetric versions can be isolated, or grouped in multiple copies (two or more assembled as shown in Fig. 8 and 11) to increase the optical performance in order to achieve the most demanding functions in luminous flux.

  The versions can be linear (Fig.8 and 11) or circular (Fig.9) or more or less curves (Fig.10), which allows an adaptation to the constraints required by the style or the form.

  Fig.12 shows a signaling device Sa linear using four main sources La average power, spaced, connected by diffusing light guides Ga. The distances between the sources La may be different.

  Of course, other arrangements are possible, with a number of different sources, especially with only two sources, one at each end of the light guide.

  According to Fig.13, the signaling device comprises only two light sources La, one at each end of the guide Gb. This guide Gb has spaced neutral zones 9, in which the outward diffusion of light has been suppressed, so that these zones 9 appear as not being illuminated. It is thus possible to obtain a "pointillist" type of signaling device as opposed to a continuous light line.

  FIG. 14 illustrates a one-piece embodiment of the signaling device Sb according to which the two opposite light guides G1, G2 form a single piece whose junction zone has a plane of symmetry P orthogonal to the longitudinal axis of the light guides. The section of the contour of the junction zone by the plane of Fig.14 has the shape of a V widely open whose branches turn their convexity to the outside. These branches then curve to join the cylindrical portion of the guide of smaller diameter than the junction area.

  A housing 10 is provided for LED 1 in the junction area. This housing 10 opens outwards through an opening 10a (FIG. 15) making it possible to insert the led 1. The inner surface of this housing comprises zones such as 11 (FIG. 16) making it possible to maintain and center the led. 1, marrying the outline of this led.

  The input faces of the light in the guides G1, G2 are constituted by the convex lenses M used to collimate the light beam in each guide, as shown schematically with two radii R1, R2 which diverge in the housing 10 before falling on the convex face of the lens M, and which become substantially parallel in the guide.

  A ray such that R3 enters the light guide beyond the contour of the lens M, undergoes internal reflections in the guide, and is returned forward.

  The housing 10 is closed, at the front, by a semi-convex lens 12 turning its convex surface 13 towards the inside of the housing 9 and having a planar face 14 towards the outside. The hemisphere of the led 1 is close by its top to the top of the face 13. The guides G1, G2 are cut along oblique facets 15 (FIG. 18) on either side of the plane face 14 of the lens, by inclined planes on the direction XX and orthogonal to the plane of Fig.15.

  FIG. 16 illustrates the path of a light beam R4 coming from the led 1 which, after crossing the lens 14, is more inclined with respect to the direction X-X.

  According to the embodiment of Fig.15 and 16, the lens 12 is integrated, that is to say forms a single piece with the guides G1 and G2.

  According to the variant of Figs.17 and 18, the housing 20 is open towards the front and an independent lens 12 is fixed in the front opening of the housing 10.

  The collimated portion formed by the rays such as R1 and R2 makes it possible to increase the luminance at the end of the guide remote from the led 1.

  According to the version of Fig.14 to 18, the signaling system is more compact, especially in its central area. The inner and outer shape of the guides, in the junction zone, is studied to optimize the flow distribution between the apparent face 14 of the central lens and the lateral light guides G1, G2. It is thus possible to adjust the relative luminance of the different zones of this signaling function.

  The homogeneous appearance of the light guides is improved by the light collimated by the lenses M. This concept can be realized in monobloc form as illustrated in Fig.14 to 18 or by assembling subsets that simplify the injection molds .

  The light guides can take three-dimensional shapes for example to follow the left surfaces characteristic of the interior passenger compartment.

  It is possible to perform the lantern function at the car headlamp with free forms.

  It is also possible to envisage a rectangular or evolving profile of the circular shape towards a rectangle by adapting the rear part to ensure a homogeneously lit aspect thanks to microstries or micro-optics.

  The invention makes it possible to obtain good signaling, with a reduced number of LEDs. The device has a great flexibility of adaptation to fulfill different functions: signaling or interior lighting using white LEDs.

  The proposed device provides style effects to ensure a signature of a vehicle using the possibilities offered by a cold light emitted by the LEDs and the property of transparent plastics to conduct light over great distances.

  The device, for its implementation, uses known manufacturing concepts: injection of parts and surface treatment by depositing a metallized film by thermal transfer, laser surface attack.

  The perceived quality of the light emitted is more intense than that obtained with a neon tube, because the LEDs emit a monochromatic light unmodified by the optical guide.

  A variant of the devices explained above is to use, as illustrated in Fig.19, a light source Le comprising several elementary sources constituted by leds lb, 1c specialized. The LEDs are fixed on a support 16 so that their main X-X emission directions are parallel.

  One or more leds ic, forming secondary side sources, send light into an associated auxiliary tubular guide G1c, G2c to increase the illuminated surface of the function. The end face 17b, 17c of the guide is inclined, for example 45, on the axis of the guide. The light emitted by the LEDs 1c in the main direction is returned by the face 17b, 17c in the corresponding guide. Preferably, there is provided a led by tubular guide.

  One or more leds lb are used to perform the main function. They are associated with one or more optical systems 18 specific to the signaling function to be performed (CHMLS, Stop / Lantern or direction indicator for example). An optical system 18 of main function can be realized in the form of a lens distributing the light in a more or less identical manner to the already described windshield 3, or via a specific reflector system according to the desired final style. The optical system 18 preferably occupies a central position while the guides G1, G2 are lateral.

Claims (16)

  Signaling or lighting device, in particular for a motor vehicle, comprising at least one light source (L, La, Lc) having a main direction (XX) of emission and at least one elongated light guide having one end is illuminated by the source, this guide being adapted to diffuse the light transversely to its length, characterized in that the light guide (Gl, G2, Gla, Glb, G2b, Ga, Gb, Glc, G2c), at least near the source (L, La, Lc), has a longitudinal axis (Y1, Y2) disposed transversely to the main direction of emission (XX) so that a part of the light flux of the source (L, La, Lc) ensures, independently of the guide, a first signaling function or lighting relatively high light intensity, and a second function of signaling or linear lighting, less light intensity, is provided along the length of the guide of light (Gl, G2, Gla, Glb, G2b, Ga, Gb, Glc, G2c).   2. Device according to claim 1, characterized in that the light source (L) is adapted to emit also in oblique directions (8), and that the source (L) provides the first signaling function or lighting, following the main direction of emission, while the second function of signaling or linear illumination is ensured along the length of the light guide (Gl, G2, Gla, Glb, G2b, Ga, Gb) by the emission in the directions obliques.   3. Device according to claim 1 or 2, characterized in that it comprises an optical system (2) associated with the light source (L) to concentrate the emission in the main direction.   4. Device according to one of claims 1 to 3, characterized in that the light source (L) comprises at least one light emitting diode (1) which illuminates substantially on a hemisphere, and the light guide (Gl, G2 Gla, Glb, G2b, Ga, Gb), at least in the vicinity of the source, has its longitudinal axis orthogonal to the main direction of emission.   5.Dispositif according to one of the preceding claims, characterized in that several light guides (Gl, G2; Glb, G2b) are associated with the same source (L, 1) being angularly distributed around the main direction of program.   6. Device according to one of the preceding claims, characterized in that the light guides (Gla; Glb, G2b) 15 are curvilinear.   7. Device according to one of the preceding claims, characterized in that the light source (L, 1) is placed in a central position between at least two light guides (G1, G2, Gla, Glb).   8. Device according to claim 3, characterized in that the optical system (2) associated with the light source comprises a lens (3) of transparent material and having facets (3a) oriented at appropriate angles to ensure internal reflections of the light before it goes out and perform a target function.   9. Device according to one of the preceding claims, characterized in that it comprises a plurality of light sources (La) connected by transverse diffusion light guides (Ga).   10. Device according to one of the preceding claims, characterized in that a light guide (Gb) comprises at least one neutral zone (9) not ensuring transverse diffusion of the light.   11. Device according to one of the preceding claims, characterized in that it comprises a convergent lens (12) oriented to create the main beam.   12. Device according to one of the preceding claims, characterized in that a converging lens (M) is provided at the end of each guide adjacent the source to collimate the light rays in the guide.   13. Device according to one of the preceding claims, characterized in that the waveguides (G1, G2) located on either side of the source form a single piece having a housing (10) for the light source. , the faces of the housing corresponding to the end of the waveguides being convex to focus the light rays in the guides.   14.Dispositif according to one of the preceding claims, characterized in that the diffusion of light through the guide is provided by a face (F) having prisms, streaks, or optical micro-patterns.   15. Device according to claim 14, characterized in that the face (F) comprising prisms, streaks, or optical micro-patterns is metallized to better reflect the light.   16. Device according to claim 1, characterized in that the source (Lc) comprises several elementary sources (lb, 1c) distributed in at least two subsets (lb, lb; lc, lc), one of these sub-units. assemblies (1b, 1b) being associated with an optical system (16) for providing a main signaling or lighting function, another subassembly (1c, 1c) cooperating with at least one lightguide (G1c, G2c) to ensure a secondary function of great length.